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This study investigated the use of K2CO3 as dietary buffer to prevent or to recover from low milk fat production when early-lactating dairy goats are fed a high-starch, low-fiber (HSLF) diet. At kidding, 30 Alpine goats housed in pens with Calan gate feeders received a total mixed ration with a forage-to-concentrate ratio of 55:45 on a dry matter (DM) basis for a baseline period of 27 ± 4 d. Goats (milk yield, 4.14 ± 0.88 kg/d; milk fat, 4.28 ± 0.52%; mean ± SD) were then assigned to 1 of 10 blocks according to parity (first vs. second or more) and milk fat concentration, and fed a HSLF diet containing 45% forages and 55% concentrates for 2 experimental periods of 28 d. Treatments were identified as (1) control, in which the HSLF diet was fed throughout both periods; (2) preventive, in which the HSLF diet supplemented with K2CO3 (1.6% of DM) was fed during both periods; and (3) recovery, in which the HSLF diet was fed during the first period (P1) and the HSLF diet supplemented with K2CO3 was fed during the second period (P2). Data from P1 and P2 were analyzed separately. In P1, preplanned contrasts were used to evaluate the preventive effect of K2CO3 (control and recovery, both groups receiving the same diet during this period, vs. preventive), and in P2, to assess the potential of K2CO3 to alleviate an already existing state of low milk fat (control vs. recovery and preventive vs. recovery). Feeding the HSLF diet in P1 moderately decreased milk fat concentration (−16%) and yield (−13%) as compared with baseline. Dietary addition of K2CO3 decreased DM intake by 12 and 14% in P1 and P2, respectively. Ruminal pH was not different among treatments. There was also no significant difference in milk yield (4.13 and 3.71 kg/d on average in P1 and P2, respectively) for any tested contrasts. In P1, milk fat concentration and yield did not differ among goats fed control (3.58% and 151 g/d, respectively) and preventive (3.67% and 148 g/d, respectively) diets. In P2, milk fat concentration and yield did not differ among goats fed the control diet (3.38% and 137 g/d, respectively), and diets where K2CO3 was used as preventive (3.44% and 126 g/d, respectively) or recovery treatment (3.25% and 113 g/d, respectively). Supplementing a high-concentrate diet with 1.6% K2CO3 was therefore not effective in either preventing or suppressing already existing conditions of low milk fat production in dairy goats.

Although future production of dairy goats is influenced by kid-rearing practices, little is known regarding which practices maximize kid growth, welfare, and future production success. The objectives of this survey study were to (1) identify common rearing practices of Canadian commercial dairy goat farms and evaluate their associations with 6 farm performance indicators and (2) determine if farms could be grouped by management style on the basis of the 6 performance indicators and compare rearing practices common across the different groups. A survey was sent by post or electronic media to reach dairy goat producers across Canada. The questionnaire contained 70 questions on the following areas of kid rearing: kidding management, care of newborn, colostrum management, milk and solid feeding in the preweaning period, health management, disbudding, housing conditions, weaning strategies, record keeping and growth monitoring, and farm performance data. Performance indicators, calculated on self-reported data, were 305-d milk production, preweaning mortality rate, diarrhea and respiratory disease prevalence, average daily gain from birth to weaning, herd milk production, and replacement rate. A total of 175 questionnaires were returned. After applying inclusion criteria, including herd size (≥40 goats) and completeness of surveys, 104 respondents from Ontario (n = 72, 69%), Quebec (n = 23, 22%), and the Western provinces (n = 9, 9%) were retained for analysis, representing 29% of all Canadian producers. Farm sizes ranged from 42 to 2,500 (median = 190) goats. A large amount of variation in rearing practices and farm performance was found between farms. Colostrum and milk feeding management were found to be associated with all performance indicators except for kid respiratory disease prevalence, with timing of colostrum delivery and feeding method accounting for most the associations within each of the 2 areas. Replacement rate was mostly affected by whether or not kids were reared with their dam. Herds surveyed in the study could successfully be divided into 3 distinct groups (production-focused, longevity-focused, and low performance), representing different management styles on the basis of farm self-reported performance levels. Rearing practices found to be associated with higher farm performance could be targeted by advisory services to help improve management practices on Canadian dairy goat farms.

This study investigated the use of dietary lipid supplements as a strategy to prevent or reduce the intensity of milk fat depression in goats fed high-concentrate diets. Thirty Alpine goats were housed in pens with Calan gate feeders at kidding, and received a total mixed ration with a forage-to-concentrate ratio (F:C) of 55:45 on a DM basis (27,4% of NDF and 17,9% of starch) during a pretrial period (23 ± 5 d). Data from the last 4 d of the pretrial period were used as covariates (d 0). Goats were blocked by milk fat concentration and randomly assigned to 1 of 3 diets containing a F:C ratio of 45:55 (25,3% of NDF and 19,4% of starch) for 41 d. Diets were: 1) Control (CTRL; no supplemental fat); 2) a high-palmitic acid diet (PALM; 16:0 at 1.9 % of DM; and 3) a high 18:3 n-3 diet (FLAX; 18:3 n-3 at 1.5% of DM). Data were collected on d 10, 20 and 41 and analyzed in a mixed model with repeated measures. In the CTRL group, feeding the high-concentrate diet reduced milk fat concentration from 4,34 to 3,53% (d 0 and 41, respectively; P< 0.01). PALM feeding increased fat yield on d 10 (12%) and 41 (21%) relative to CTRL and on d41 relative to FLAX (16%; all P< 0.05). No treatment effect was observed on ruminal pH (6,32; P >0.93) and individual volatile fatty acids (P>0,12). However, the concentration of ruminal propionate increased from 17.9 to 20.3%, while acetate and the acetate: propionate ratio decreased respectively from 68.1 to 62.0% and from 4.21 to 3.19 (P< 0.01) on d 41, relative to d 0. Feeding PALM can alleviate the reduction of milk fat synthesis in goats receiving high concentrate diets in early lactation. Key Words

Changes in climate and ultraviolet radiation levels in the Arctic will have far-reaching impacts, affecting aquatic species at various trophic levels, the physical and chemical environment that makes up their habitat, and the processes that act on and within freshwater ecosystems. Interactions of climatic variables, such as temperature and precipitation, with freshwater ecosystems are highly complex and can propagate through the ecosystem in ways that are difficult to project. This is partly due to a poor understanding of arctic freshwater systems and their basic interrelationships with climate and other environmental variables, and partly due to a paucity of long-term freshwater monitoring sites and integrated hydro-ecological research programs in the Arctic. The papers in this special issue are an abstraction of the analyses performed by 25 international experts and their associated networks on Arctic freshwater hydrology and related aquatic ecosystems that was initially published by the Arctic Climate Impact Assessment (ACIA) in 2005 as "Chapter 8--Freshwater Ecosystems and Fisheries". The papers provide a broad overview of the general hydrological and ecological features of the various freshwater ecosystems in the Arctic, including descriptions of each ACIA region, followed by a review of historical changes in freshwater systems during the Holocene. This is followed by an assessment of the effects of climate change on broad-scale hydro-ecology; aquatic biota and ecosystem structure and function; and arctic fish and fisheries. Potential synergistic and cumulative effects are also discussed, as are the roles of ultraviolet radiation and contaminants. The nature and complexity of many of the effects are illustrated using case studies from around the circumpolar north, together with a discussion of important threshold responses (i.e., those that produce stepwise and/or nonlinear effects). The issue concludes with summary the key findings, a list of gaps in scientific understanding, and policy-related recommendations.

Large variations exist in the size, abundance and biota of the two principal categories of freshwater ecosystems, lotic (flowing water; e.g., rivers, streams, deltas and estuaries) and lentic (standing water; lakes, ponds and wetlands) found across the circumpolar Arctic. Arctic climate, many components of which exhibit strong variations along latitudinal gradients, directly affects a range of physical, chemical and biological processes in these aquatic systems. Furthermore, arctic climate creates additional indirect ecological effects through the control of terrestrial hydrologic systems and processes, particularly those associated with cryospheric components such as permafrost, freshwater ice and snow accumulation/ablation. The ecological structure and function of arctic freshwater systems are also controlled by external processes and conditions, particularly those in the headwaters of the major arctic rivers and in the adjacent marine environment. The movement of physical, chemical and biotic components through the interlinked lentic and lotic freshwater systems are major determinants of arctic freshwater ecology.

Climate change is likely to act as a multiple stressor, leading to cumulative and/or synergistic impacts on aquatic systems. Projected increases in temperature and corresponding alterations in precipitation regimes will enhance contaminant influxes to aquatic systems, and independently increase the susceptibility of aquatic organisms to contaminant exposure and effects. The consequences for the biota will in most cases be additive (cumulative) and multiplicative (synergistic). The overall result will be higher contaminant loads and biomagnification in aquatic ecosystems. Changes in stratospheric ozone and corresponding ultraviolet radiation regimes are also expected to produce cumulative and/or synergistic effects on aquatic ecosystem structure and function. Reduced ice cover is likely to have a much greater effect on underwater UV radiation exposure than the projected levels of stratospheric ozone depletion. A major increase in UV radiation levels will cause enhanced damage to organisms (biomolecular, cellular, and physiological damage, and alterations in species composition). Allocations of energy and resources by aquatic biota to UV radiation protection will increase, probably decreasing trophic-level productivity. Elemental fluxes will increase via photochemical pathways.

Various types of ecosystem-based climate proxies have been used to assess past arctic change. Although lotic records are relatively poor because of the constant reworking of riverine material, high-quality lentic data have been assembled back to the end of the Pleistocene and deglaciation of the circumpolar Arctic. In general, climatic variations in the Holocene, partly due to changes in the shrinking effect of glacier coverage, produced significant temporal and spatial variations in arctic hydrology and freshwater ecosystems. Of particular note were the vast expansions of northern peatlands during major protracted periods of wetting. More recent lake biota and sedimentiological data reflect the general warming trend that has occurred over the last one to two centuries and indicate major changes to freshwater characteristics such as ice-cover duration and thermal stratification. Such data provide an excellent baseline against which future effects of climate change can be both projected and measured.

A better knowledge of intramuscular fat (IMF) content distribution would allow the identification of a predictive site on the longissimus muscle to assess the total IMF content. For this purpose, 50 commercial crossbred pigs of both genders were selected live with ultrasound equipment at the 3rd/4th last rib in order to provide backfat differences varying from 10 to 34.7 mm. Left longissimus muscles were deboned and sliced every 2 cm from the posterior (3rd last lumbar vertebra) to the anterior (5th thoracic rib) end. In all, 14 locations on the longissimus muscle were established and labeled as T5-T14 (thoracic region) and L1-L4 (lumbar region). The slices were used for subjective marbling evaluation and for intramuscular fat content (IMF) measurement. The results showed that total IMF content and marbling scores were correlated (r = 0.86) and followed a similar pattern, with highest values being obtained in the middle section of the thoracic region and in the middle-caudal section of the lumbar area. In addition, both IMF content and marbling scores were anatomical location dependant. Gender did not affect IMF content, but influenced marbling score, castrates being more marbled (score: 2.77 vs. 2.35) than females. The IMF content (R2: 0.94–0.95) and marbling score (R2: 0.7–-0.81) were the best predictors of mean IMF when measured at or near the grading site (3rd/4th last rib). Key words: Pork, intramuscular fat, marbling score, longissimus muscle, within muscle variation

s S25 049 PLATELET REACTIVITY, P2Y12 RECEPTOR INHIBITOR SELECTION AND CLINICAL OUTCOMES IN PATIENTS WITH ACUTE MYOCARDIAL INFARCTION TREATED WITH PERCUTANEOUS CORONARY INTERVENTION: INSIGHTS FROM THE TRANSLATE-ACS STUDY A Bagai, ED Peterson, L McCoy, MB Effron, GW Stone, TD Henry, DJ Cohen, PJ Schulte, KJ Anstrom, TY Wang

Ten Holstein cows in early lactation were used in a replicated 5 x 5 Latin square design to study the effects of MgO and three buffers added to diets containing Ca salts of canola oil fatty acids. Treatments were 1) control (basal diet; no buffer). 2) 1.1% NaHCO3 plus 1.1% KHCO3, 3) 1.9% NaHCO3, 4) 0.5% MgO, and 5) 2.0% Na sesquicarbonate (percentage of dry matter). The control diet contained 53% grass silage, 43% concentrate, and 4% Ca salts. Body weight, intake, milk yield, and percentages of milk fat, protein, and lactose were unaffected by treatments. Buffers and MgO tended to increase triacylglycerol extraction by the mammary gland and changed the proportions of some fatty acids in milk. Arterial concentrations of acetate and triacylglycerol were correlated with their respective arteriovenous differences. Extraction by the mammary gland was high for acetate (approximately equal to 58.2%), triacylglycerol (approximately equal to 47.3%) propionate (approximately equal to 34.6%), and glucose (approximately equal to 24.3%). Extraction of free fatty acids, phospholipids, or cholesterol was negligible. Mammary triacylglycerol arteriovenous difference tended to be higher than when MgO was fed than when NaHCO3 was fed. Sodium sesquicarbonate, NaHCO3, and the blend of bicarbonate buffers increased C18:2 in milk fat when compared with the control treatment. The concentration of C18:2 in milk fat decreased when MgO was fed, but the ratio of cis-C18:1 to trans-C18:1 increased compared with effects of dietary NaHCO3. Medium-chain fatty acids in milk fat tended to be higher than Na sesquicarbonate than with NaHCO3. Buffers and MgO modified the profiles of fatty acids in milk.

The effects of dietary supplements of folic acid on growth performances and haematological and hepatic variables of white veal calves were studied in 90 young dairy calves. From the age of approximately 2 weeks, they received twice daily 0, 4 or 16 mg of supplementary folic acid added to the milk replacer. They were fed exclusively milk replacer for 105 days. Supplements of folic acid increased serum (P⩽0.05) and red blood cell (P⩽0.05) folate concentrations, and slowed the decrease with age of haemoglobin and packed cell volume (P⩽0.05). The addition of 4 or 16 mg of folic acid twice daily to the milk replacer increased hepatic folates by a factor of 39.5% and 57.4%, respectively, as compared to controls (P⩽0.05). Folic acid improved growth (P⩽0.05), but had no effect on feed intake (P>0.05). Time required to reach 180 kg decreased linearly as supplements of folic acid increased (P⩽0.05). Calves receiving 0, 4 or 16 mg of folic acid twice daily reached 180 kg in 95.3±2.7, 89.9±1.l, or 88.7±1.4 days, respectively. It was concluded that dietary supplements of folic acid improved haematological variables and shortened the rearing period of white veal calves without increasing their feed intake.

It often takes one single event to interest teenagers in a topic that will become a passion or a career. It is in this spirit that the SPIE and OSA Student Chapters at UniversitAƒÂ© Laval created the Photonic Games three years ago, to kindle an interest in teenagers towards studies and careers in optics. The activity, offered each year to more than a hundred grade 11 students, is divided in two parts. First, we offer a hands-on workshop in their classrooms about reflection, refraction, dispersion, birefringence and polarization. A few days later, all the students come to the Centre d'optique, photonique et laser (COPL) at UniversitAƒÂ© Laval for a day of competition where a volunteer physics student accompanies each team of four students. Challenges are various to promote the qualities that make great scientists: creativity, teamwork, knowledge, inquisitiveness, self-confidence and perseverance. The first two editions of the Photonic Games have proven to be beneficial for the students, teachers and volunteers, and we endeavor to improve it as we construct on our experience with the past editions to fine-tune and improve the Photonic Games concept.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The effect of dietary supplemental folic acid on serum folates of preruminant and ruminant calves was studied. In Trial 1, doses of 0, .07, .14, .28, and .56 mg of folic acid per kilogram of BW were added to the milk of preruminant calves. In Trial 2, doses of 0, .5, 1, 2, and 4 mg of folic acid per kilogram of BW were incorporated into the concentrates of ruminant heifers. In the first part of each trial, serum folates were determined in blood samples taken 0, 1, 2, 4, 8, 16 (both trials), and 32 h (Trial 2) after a single meal supplemented with folic acid. In the second part of the two trials, the supplement of folic acid was given in feed during seven consecutive days. Blood samples were taken the day before the trial and subsequently every day during 7 d. In preruminant and ruminant calves, the area under the curve and the peak of concentration of serum folates after a meal increased with the dose ingested (P less than or equal to .05, linear and quadratic effect of doses, respectively) but the amount of folic acid needed to obtain a similar response was lower for preruminant than for ruminant calves. In preruminants, the time to reach the maximal concentration was 3 to 4 h after the meal, whatever the dose ingested (P less than or equal to .05), whereas in ruminants this time decreased with the dose ingested (quadratic effect of treatment, P less than or equal to .05).(ABSTRACT TRUNCATED AT 250 WORDS)

In general, changes in climate and UV in the Arctic will have far-reaching impacts, affecting aquatic species of varying trophic levels, the physical environment that makes up their habitat and the chemical properties of that environment, and the processes that act on and within freshwater ecosystems. Interactions of climatic variables such as temperature and precipitation with freshwater ecosystems are highly complex and can be propagated through the ecosystem in ways that are not readily projectable. This reduces our ability to accurately forecast specific effects of climate and ultraviolet-radiation change upon freshwater systems. This is particularly the case when dealing with threshold responses, i.e., those that produce step-wise and/or non-linear effects. Our ability is further hampered simply by our poor understanding of Arctic freshwater systems and their basic interrelationships with climatic and other environmental variables, as well as by a paucity of long-term freshwater monitoring sites and integrated hydroecological research programs in the Arctic. A significant amount of the understanding of potential impacts is based on historical analogues (i.e., historical evidence from past periods of climate change), as well as from a limited number of more recent studies of ecosystem response to environmental variability. Paleoreconstructions indicate that during the most recent period of climatic warming, which followed the Little Ice Age, the Arctic reached its highest average annual temperatures observed in the past 400 years, resulting in glacier retreat, permafrost thaw, and major shifts in freshwater ecosystems. Examples of ecosystem effects included altered water chemistry, changes in species assemblages, altered productivity, and an extended growing-season length. Importantly, however, past natural change in the Arctic occurred at a rate much slower than that projected for anthropogenic climate change over the next 100 years. In the past, organisms had considerable time to adapt; their responses may therefore not provide good historical analogues for what will result under much more rapid climate change. In many cases, the adaptability (i.e., adaptation, acclimation, or migration) of organisms under rapidly changing climate conditions is largely unknown. Unfortunately, no largescale attempts have been made to study the effects of rapid climate change on aquatic ecosystems using controlled experiments, as have been attempted for terrestrial systems (e.g., see International Tundra Experiment studies of tundra plant response in (1). However, field studies in areas that have recently experienced rapid changes in climate have provided important knowledge. Information about ongoing climate change impacts is provided by results from long-term environmental monitoring and research sites in the Arctic, including the case studies used in this assessment (i.e., Northern Quebec and Labrador, Canada (see 2), Toolik Lake, Alaska and Lake Saanajarvi, Finnish Lapland (see 3), and the Zackenberg Valley in northeastern Greenland (see 4).

In general, the arctic freshwater-terrestrial system will warm more rapidly than the global average, particularly during the autumn and winter season. The decline or loss of many cryospheric components and a shift from a nival to an increasingly pluvial system will produce numerous physical effects on freshwater ecosystems. Of particular note will be reductions in the dominance of the spring freshet and changes in the intensity of river-ice breakup. Increased evaporation/evapotranspiration due to longer ice-free seasons, higher air/water temperatures and greater transpiring vegetation along with increase infiltration because of permafrost thaw will decrease surface water levels and coverage. Loss of ice and permafrost, increased water temperatures and vegetation shifts will alter water chemistry, the general result being an increase in lotic and lentic productivity. Changes in ice and water flow/levels will lead to regime-specific increases and decreases in habitat availability/quality across the circumpolar Arctic.

Climate change is projected to cause significant alterations to aquatic biogeochemical processes, (including carbon dynamics), aquatic food web structure, dynamics and biodiversity, primary and secondary production; and, affect the range, distribution and habitat quality/quantity of aquatic mammals and waterfowl. Projected enhanced permafrost thawing is very likely to increase nutrient, sediment, and carbon loadings to aquatic systems, resulting in both positive and negative effects on freshwater chemistry. Nutrient and carbon enrichment will enhance nutrient cycling and productivity, and alter the generation and consumption of carbon-based trace gases. Consequently, the status of aquatic ecosystems as carbon sinks or sources is very likely to change. Climate change will also very likely affect the biodiversity of freshwater ecosystems across most of the Arctic. The magnitude, extent, and duration of the impacts and responses will be system- and location-dependent. Projected effects on aquatic mammals and waterfowl include altered migration routes and timing; a possible increase in the incidence of mortality and decreased growth and productivity from disease and/or parasites; and, probable changes in habitat suitability and timing of availability.

Detailed results of numerical one-dimensional wave-packet simulations are reported for the dynamics of a ${\mathrm{D}}_{2}^{+}$ molecule subjected to separated and combined 400-nm and 800-nm intense laser pulses with their polarization vectors lying either parallel or perpendicular to the internuclear axis of the molecule. Depending on the laser excitation conditions, the model employed involves from four to a maximum of eight electronic channels, comprising molecular states correlating, in the dissociative limit, with the $n=1$ shell of atomic hydrogen and those correlating with the $n=2$ shell. Preliminary results of calculations including molecular rotations within a two-dimensional model are also reported. Overall, calculated fragment kinetic-energy spectra, the main results of the present work, are in accord with the findings of recent experimental works [Talebpour et al., Phys. Rev. A 62, 042708 (2000); Vijayalakshmi et al., ibid. 053408 (2000)], which reported evidences of perpendicular dissociation induced by intense 400-nm and 800-nm laser pulses. These results are thus supportive of the hypothesis made therein of perpendicular transitions to upper molecular excited states, through a ${\ensuremath{\pi}}_{u}$ doorway. Deviations from the predictions of the Floquet schemes proposed in these works are discussed in terms of the laser-driven rotational dynamics of the molecular ion and in terms of bond-softening versus bond-hardening effects.

Anaerobic degradation of pentachlorophenol (PCP) is an example of a process that may benefit from enrichment or bioaugmentation. In one approach, enrichment acceleration was attempted by applying an on-line control-based selective stress strategy to a native anaerobic upflow sludge bed (UASB) system; this strategy linked PCP loading rate to methane production. As a result, the reactor biomass potential for PCP complete dechlorination reached a rate of 4 mg g(-1) volatile suspended solid (VSS) day(-1) within a period of 120 days. In another approach, a pure culture, Desulfitobacterium frappieri PCP-1, a strictly anaerobic Gram-positive bacterium, was used to augment the granular biomass of the UASB reactor. This also resulted in a specific degradation rate of 4 mg PCPg(-1) VSS day(-1); however, this potential was attained within 56 days. Fluorescent in situ hybridization (FISH) showed that the PCP-1 strain was able to rapidly attach to the granule and densely colonize the outer biofilm layer.

Twenty-four multiparous Holstein cows, 4 of which were ruminally fistulated, were assigned to one of four diets containing full-fat soybeans, either raw or extruded at 120, 130, or 140°C. Our hypothesis was that the extrusion of full-fat soybeans, as well as the extrusion temperature, would affect the bypass of fatty acids in the rumen and, thus, would modify the fatty acid profile of milk fat. Total mixed diets containing 23.7% soybeans (percentage of DM) were fed for 8 wk. Milk yield was lower, and the proportion of milk CP was higher, for cows fed raw soybeans than for cows fed extruded soybeans. Compared with raw soybeans, extruded soybeans increased the concentration of Δ-11- trans -C 18:1 from 2.72 to 11.41% in milk fat but had no effect on yield or percentage of milk fat. Polyunsaturated fatty acids of raw soybeans disappeared more rapidly than did those of extruded soybeans from bags incubated in the rumen of fistulated cows. However, more Δ-11- trans -C 18:1 and C 18:0 appeared in bags containing extruded soybeans than in bags containing raw soybeans. Extrusion of full-fat soybeans influenced the metabolism of fatty acids in the rumen and the fatty acid profile of milk fat, but the temperature of extrusion had only minor effects on these parameters.